Check for invalid length in the X.509 version field

If such an invalid length is detected, reject the certificate.
Reported by Hanno Böck.

1 files changed, 10 insertions, 1 deletions

diff --git a/lib/x509/x509.c b/lib/x509/x509.c
index 8e5948becf..d4df162712 100644
--- a/lib/x509/x509.c
+++ b/lib/x509/x509.c
@@ -347,7 +347,13 @@ gnutls_x509_crt_import(gnutls_x509_crt_t cert,
 	}
 
 	/* enforce the rule that only version 3 certificates carry extensions */
-	version = gnutls_x509_crt_get_version(cert);
+	result = gnutls_x509_crt_get_version(cert);
+	if (result < 0) {
+		gnutls_assert();
+		goto cleanup;
+	}
+
+	version = result;
 	if (version < 3) {
 		gnutls_datum_t exts;
 		result = _gnutls_x509_get_raw_field2(cert->cert, &cert->der,
@@ -741,6 +747,9 @@ int gnutls_x509_crt_get_version(gnutls_x509_crt_t cert)
 		return _gnutls_asn2err(result);
 	}
 
+	if (len == 0)
+		return gnutls_assert_val(GNUTLS_E_CERTIFICATE_ERROR);
+
 	return (int) version[0] + 1;
 }